<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

</body>
<script>
    // 1- 对象的属性类型是字符串
    // const obj = {};
    // const obj2 = {a:1};
    // const obj3 = {b:2};
    // obj[obj2] = 100;// obj["[object Object]"] = 100;
    // obj[obj3] = 200;// obj["[object Object]"] = 200;
    // console.log(obj,obj[obj2],obj[obj3]);//console.log(obj["[object Object]"],obj["[object Object]"])

    // console.log(obj2.toString())// [object Object]
    // console.log(obj3.toString())// [object Object]


    var a = {
    };
    var b = {b:1};
    var c = {c:2};
    a[b] = 4;
    a[c] = 5;
    console.log(a[b]);
</script>
</html>